Driving mechanism for oil-well pumps



E. c, EKsTRoM'ER 1,799,458 Y April 7, 1931.

EcHANIsM FOR om WELL PUMPS I DRIVING M 'Filed Marc 12, 1930 2 Sheets-Sheet l .4 Hifi@ hMW/WWMWV m illmwslll TORNEY April 7, 1931..

E. C. EKSTROM ER D'IVING MECHANISM FOR OIL. wEIL PUMPS 1930 2 lSheets-Sheet 2 Filed March 12 INVETOR.

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Patented Apr.. 7,A 1931 UNITED STATES 4inaffida-NT"-.ol-"rice l EDWARD c. EKs'rRoMER, 0E REDwooD CITY, CALIFORNIA, AssIGoR or ONE-HALF To i JAMES E. GALLAGHER, oF BERKELEY, CALIFORNIA, AND ONE-HALF To THE ED- WARD `C. EKSTROMER CORPORATION, A CORPORATION OF NEVADA.

DRIVING MECHANISM lFOR OIL-WELL PUYPS Application nlea'iaarch 12, 1930.r serial N6. '$135,141.

y My present invention -relates broadlyto apparatus for converting rotary motion into reciprocating motion, and more particularlyto an improved arrangement of apparatus of the above character for driving reciprocating oil well pumps having a relatively long stroke.

-The object of my invention is to provide an improved oil well pump driving mechanism 10 which can be lowered 1nto an 011 well as 'a unit upon the lower end votthe oil discharge ipe.

Another object of my invention. is to'pro-l vide an electrically driven reciprocating pump 4unit for deep well pumping that can be lowered into the well at the end of the oil discharge pipeandin which there isprovided rotary electric motors and means for 'l the top of the well.

a walking beam -which is oscll-v *are stretching,

converting the rotary movement of said motor y into a reciprocating movement which canpbe imparted to the pump sucker rod.`

A further object of my invention is to provide a new and improved apparatus for-converting the rotary motion of an electric m07 tor into a reciprocating motion, which when connected to a pump will operate the sucker rod with a reciprocating movement.

' Other objects and advantageous features ot my invention will be in part evident and 1n' part set forth at length inthe following description wherein I have outlined in full that fornrot apparatus which I have selected for illustration 'in the drawings accompanylng and forming a part of this specification.

At the present time, n reciprocatingtype are operated by means of amotive'power unit located. on the surface at These units comprise a. prime power, lated by means of a pitman connected to the prime mover and'a sucker rod'whiehis attached to,- the walking beam and caused to move with 'a reciprocating movement as the walking beam is oscillated'. The sucker rod extends downwardly. into the well vwhere Vit connects to the moving parts of thepump.

Theuse of such a sucker rod is attended with Imany undesirable features, some of which i whipping, and its weight. All of these undesirable features'becomemore for such a purpose.

oil well pumps of the exaggerated as the d epth of the Well increases and itis therefore desirable that some means be providedwhereby these diiiiculties can be overcome'. i l

vIn order to overcome these diiiculties, I

propose to construct a primemover element for operating a reciprocating oil well pump that can be lowered into the welland which will dispense with the use of the above referred to motive power units and its'cooperating sucker rod. The greatest obstacle'in providing such a unit is in providing a unit small enough to be inserted into the well casing, which casing is of a relatively small diameter This restriction in the sizeof such a unit, however, applies only to.

its horizontal or diametrical dimensions and since it can'be made of almost any desired length, I propose to ,build an electro-mechanical power unit lby employing a plurality of smaller units, each of which is small enough to be inserted inthe well. i

i For a better understanding of my invention, reference l panying drawings, in which I have shown'by way` of illustration and not of limitation ap-v should be hadV to the accom i paratus which represents the best embodi- -ment of my devlcenow known to me. desire to have it understood, however, that many 'changes and modifications can be made there- 'in without departing from the spirit of my invention,

In the drawings,wherein like numeralsrei fer to like parts throughout the several views, Fig. 1 is a vertical sectional view 'of the lower portion of my improved pump and driving mechanism,

Fig. 2 1s a vertical sectional-view of the -I middle portion of my improved mechanism,

Fig. 3 is a vertical sectional view of the upper portion of my improved pump driving mechanism,

Fig. 4 is a vertical sectional view of apart ot thel mechanism taken on a planeat right angles to the plane of the sections shown in -f Fig.3,ff .l l-

Figs, 5 and 6 are fragmentary vertical sectional views of the pump portion ofmy im'- proved device, ,y

Fig. is a fragmentary vertical' sectional view of the reciprocating driving mechanism of my invention,

Fig. 8 is alfragmentary vertical sectional view showing stop devices which co-operate with the apparatus shown in Fig. 7, A

Figs. 9, 10 and 11 are horizontal sectional views taken respectively along lines IX-IX, X-X and XI-XI of Figs. 7 and 8, and

Fig. 12 is a fragmentary detailed view in elevation showing the toggle mechanism.

In the drawin s 10 designates an outer casing which is pernrated throughout its length by the provision of suitable apertures 11 extending through the sides thereof. At the lower end of the outer casing 10 there is provided ai suitable closure member 12 and attached to this closure member 12 and extending upwardly within the outer casing 10 there is a second or inner casing 13. The casing 13 is spaced from the outer casing 10 Vso as to prpvide an annular passageway14 between the two casings through which the oil to be pumped may freely pass as will hereinafter be apparent..

Arranged within the inner casing 13 and at the lower end thereof as illustrated in Fig. 1, there is provided a plurality of induction motor units 15 which are connected together by suitable enclosed flange couplings 16.

Disposed above the motors 15 there is also provi ed an epicyclic reduction gear mechanism 17 which is adapted to transmit the high v.speed rotary movement of the motors to a aft 18 at a lower speed. The shaft 18 is shown as connected to the epicyclic gear 17 through a coupling 16 similar to that disposed between the motor units 15, and surrounding the shaft 18 there is provided a' suitablepackln support 19 in. which there is arranged pac ings 20 and 21 for the `purp ose of preventing a free flow of oil along the shafts at these points.

Formed integrally upon the shaft 18, or connected thereto by suitable couplings, there is provided a right and left hand spirally threaded section of shaft 22 which is adapted to be rotated continuously in one direc' tion by the motors 15. The spirally threaded portion 22 of the shaft 18 is suitably supportedupon roller bearings 23 and 24, as willhereinafter appear. Surrounding the irally threaded shaft 22 I provide a suita le cylindrical casing'25 which is adapted to reci rocate axially Within the inner casing 13 an along the spirally threaded portion 22 ofthe shaft 18. This casing 25 carries suitable nutsand other mechanism' which are to be described in greater detail hereinafter. Projecting upwardly from the casing 25 I show a pair of connecting links 26 which are connected together at their. up er ends by means of a portion 27 so as to orm4 a yokelike member. rThese links 26 are disposed so that they ass beyond the upper bearing support of t e spirally threaded shaftl 22 and connect 'with a sucker rod 28 of a suitable pump 29.

All of the aforementioned parts of m im proved device with the exce tion o the sucker rod 28 and pump 29 are disposed within the inner casing 13. At the upper end lof the inner casing 13 where the sucker rodV 28 emerges therefrom there is provided additional packings 29 and 30 which serve to prevent the admission of crude oil into the inner casing. The inner casing 13 as shown in ^Fig. 3 terminates at the packing 30, and from this point on the outer casing continues to a point where it is connected with a suitable ported fitting 31 which is adapted to establish a connecting passageway from the space between the casings 10 and 13 to the intake end of the pum 29.

In Fig. 4 the mem er 31 is shown as having two oppositel disposed ports 32 that merge into a sing e annular port 33 which communicates with the intake end of the pump 29.

As shown in Figs. 5 and 6 the pump is of the usual construction such as is provided in long stroke pumps of this character. p In other words, it consists of a suitable piston 34 having packings35 and a ball valve 36 at the lower end thereof. At the upper end of the pump there is also provided a suitable check valve 37. The pump 29 at its upper end asy is attached to an oil discharge pipe 38 which ,paratus in the well.

Before proceedin with a description of the apparatus as li ustrated inV Sheet 2 of the drawings, mention should be made of the manner of supplying the motors 15 with electric power'. This is done by means of a three phase concentrically formed cable which extends downwardly into the oil well alon side the discharge pipe 38. The lo`wer end o this cable extends 1nto a terminal box 39 formed upon the ittin 31, as shownl in Fig. 3. From the terminal ox '39 three individual conductors extend downward in a suitably formed .passageway and between the casings 10 and 13 to the several motor units 15.

In order to hold the casing 25 against rotation as the shaft 22 fr'tates, there is provided oppositely disposed keys 41 which project inwardly from the inner wall of the inner casing 13. These keys 41 extend "along the walls of the inner casing 13 throughout the length of travel of the casing 25 and engage keyways 42 formed along opposite sides f secured substantially midway between they ends of the casing by means of screws 46.

At the outerends of each of the nuts 43 and 44 the casing 25 is provided with'end members 47 and 48 which are also secured to the casing by means .of screws. Suitable ball I bearings 49 and 50 are provided at the top and bottom of the nut 43, as are 'also similar bearings 5l and 52 at the top and bottom of the nut 44. The provisions of these bearings at the ends of the nuts 43 and 44 it will be understood, is to permit their free rotation when the shaft 22 rotates, so that when one nut is released it will ride freely up or down the shaft as-the casing is driven by the other nut.

In det-ail, the nuts 43 and 44 are in every respect similar except that they are disposed in reversed positionsupon the shaft 22. Be-

cause of this similarity, and in order to simplify my eseription, I shall only describe here the nut 43 and its co-operating parts. It will be understood that the description of nut 43 and its co-operating parts will' also apply to the nut 44 and its co-operating parts.

Onthe upper end of the nut 43 there is formed a conicalhead 53 and firmly fixed A to .the nut along a portion of its length there is provided a number of conical lmembers 54 which form a series of lcone surfaces 011 the nut. Surrounding these cone surfaces there'l is also provided a corresponding number of conical ring-shaped members 55 which are adapted to frictionally engage the'aforementioned conical surfaces upon the nut. .The comcal ring members 55 are keyed -against rotation in the casing 22 but are free' to move axially thereof so that.y when they lzontally disposed circular toggle 59. The

bottom of this toggle mechanism rests upon `a 4supporting seat or abutment 60 so that w en the toggles 58 are extended, thecone clutches formed by the cone members 54 and conical rings 55 will be engaged and thus grip the nut 43 and hold it against'rotation with- A'GO in the casing 25. The supporting seat or abutment 60 is carried upon a plurality of relatively still' compression springs 61, which may be adjusted to providethe rightamount of pressure when the clutches 'are engaged. At the upper end of the nut 43 there is also te provided an additional set of relatively weaker springs 62 which tend to dise-ngage the clutch members when the toggles 58 are collapsed.

Connected to the horizontally disposed tog- A gle/59 of the nut 43 and to a simi arl toggle 59 of the nut 44 there is shown a pair of:

rods 63.l These rods extend in both directions from the toggles and project beyond the ends of-the casing 25,- where they are provided with flat annular plates 64 which surround the screw 22..' These rods 63 are adapted to freely slide through the casing 25 and are attached to the toggles 59 and 59 so that when one is extended the other will be col- 63 it will be seen thatas they are moved up and down the casing 25 the toggles will be alternately extended and collapsed.

In order to control the actuation of the toggle mechanism, I provide suitable latching means at each end of the casing in the form of oppositely disposed latches which engage the plate 6411s is clearly illustrated in Fig. 8 of the drawings.

Upon referring to this latter figure of the 'axially' extending and oppositely disposed I lapsed. With4 this arrangement of the rods drawings it will be seen that the latches 65 at the top of the casing 25 have engaged the adjacent annular plate 64 and are holding the rods 63 in their uppermost position. It will also be seen that the latches 65 at the bottom of the casing 25 have released th adjacent plate 64 at thispoint.

When the parts are in the position here shown, the nut 43 will be held in clamped en. gagement with the easing 25 and as a result the whole assembly will be' traveling upwardly along the shaft 22. As the casing 25 approaches the -upper end of its travel the latches 65 'will be engaged by an annular collar 66 which will, as thecasing continues to move upwardly, move the latches 65 outward-4- ly and 4cause them to release thel plate 64 and the rods 6 3. Prior to the engagement of the. latches 65 with the member 66. the plate 64 will, however, have engaged a yielding sleeve 67 which is yieldingly held by means of a spring 68 carried within a stationary housing 69 secured to theinner casing 13, as illustrated inFig. 9. The yielding sleeve 67 is so proportioned'that it will store up en-A ergy just prior to the release of the latchesA 65 and expend its energy to push the rods 63 downwardly and thus collapse the t ggle 59 and extend the toggle'59.

The travel of the sleeve 67l is'A designed to be sufficient to forcekthe rods 63 downwardlyl far enough to permit theA lower latches 65 engaging and holding the lowery annular plate 64 .in this second orlowermost position. Ar-

ranged adjacent to the lower end ofthe screw shaft 22 there is also provided a housing 70 that carries parts corresponding to those just described in connection with the housing 69,

which parts function in a similar manner to reverse the action of the toggle mechanism and thus cause the casing to again travel when the mechanism is operating on the uptoggle 59 and extend the tog le 59.

stroke of the pump, which is the power stroke, the .screw 22v will be placed under tension rather than compression and as a result a bowing of the shaft 22 will be prevented.

Figs. 10, 11 and 12 show various details of construction which is believed will-be readily understood without a further description thereof.

The o eration of my improved mechanism is as fo lows:

It will be assumed that the motors 15 have been energized and are rotating at the proper speed and that the epicyclic gear 17 is transmitting a suitable rotary movement to the shaft 18. This will cause the spirally threaded portion of shaft 22 to rotate and when the parts contained in the casing 25 are in the position shown in Fig. 7, the 'casing 25 will be moving upwardly as a result of the nut 4 3 being engaged by the clutch Vmembers prevlously described. As the casing 25 moves upwardly it will transmit through the oppositely disposed rods 26 an upward movement of the sucker rod 28 which will im art a similar movement to the piston 34 o the pumpV 29, as will be readily understood.

lVhen the ,parts reach the position illustrated in Fig. 8 the latches 65 will engage the annular member 66 and be forced out- .wardly to a position where they will release the upper plate 64y carriedy by the rod 63, andthe previously stored energy l of the spring 68 will act through sliding sleeve 67 to force the rods 63, which are attached to the Jtoggles 59 and 59', andthus collapse the en thetoggle 59 is collapsed .t e nut 43 will be released a'nd ma 'then freely turn as it slides down the sha t 22. 'Atthe' vsame time the nut 44 will be firmly `'gripped against rotation within the casing 25 andwill travel down the shaft 22 by reason of its-spiral en- `gagement therewith and thus carry the casing 25 and its attached mechanism downwardl until the lowermost tpggles 65, which wil now be in their latching position, are released land the above operation again repeated.

While I have, for the Isake of c earness and l yin vorder -to disclose ymy invention so that the same can be readily understood, described and illustrated specific devices -and arran ements, I desire to haveit understood that t is invention is not limited to the specific form disclosed but may be embodied in other ways that will suggest themselves, in lview of-this broad disclosure, to persons skilled in the art.

p lIt is believed that this invention is broadlyA to be driven there along when held against rotation, one of said nuts having a right-hand thread and the other a left-hand thread, a casing surrounding said nuts having connection with a reciprocatable element, and means carried by said casing adapted to automatically grip said nuts alternately to thereby cause said-casing and said reciprocatable element to move with a reciprocating movement as said screw is rotated.

'2. A driving mechanism for reciprocating pumps andthe like comprising, a double acting screw adapted to be vdriven in one direction, a pair of nuts upon said screw adapted to be driven there along when held against, rotation, one of said nuts having a right-hand thread and theother a left-hand thread, a

casing surrounding said nuts having connection with a reciprocatable element, friction clutches carried by said casing adapted to automatically grip said nuts alternately as they reach the endof their travel, and means Jfor alternately actuating said clutches to thereby cause said casing and said reciprocatable element to move with a reciprocating movement as said screw ously in one direction. y. v

3. A driving mechanism for reciprocating umps and the like comprising, a right and riven in one directiongtravehng nuts upon 4left-hand threaded screw adapted to be is rotated ,continu-l 1 said screw havingthreads 'cut in right and left-hand relation and adapted to be driven there along when held against rotation, a casing surrounding said nuts having cnnection with' a reciprocatable element, nut gripping means carried by said casing adapted to alternately grip said nuts to thereby cause first one nut and then the other to be driven along said screw, and means for limiting the travel lof said casing adapted to actuate said gripping means,l whereby said casing andA said reciprocatable element will be automati- --cally moved with a reciprocating movement as said screw is rotated.

4. A driving mechanism for converting rotary motion into a reciprocating motion comprising, a shaft having right and lefthand spiral threads formed thereupon, right and vleft-hand nuts in threaded engagement lwith said .shaft adapted. to be, driven there along .when held against rotation, al casing Asurrounding said nuts adapted to hold them in spaced relation `and freely rotatable, a an operative position when extended, and a yoke Acarried by said casin 'adapted to conthird toggle aving blfurcated arms whlch neet with a reciprocatable e ment, co-o eratstraddle said shaft .adapted to. extend said ing cone clutch members carried by sai nuts first toggles when 1t 1s extended.

5 and said casing, means co-operating with said EDWARD C. EKSTROMER. 7 0

cone clutch members adapted when actuated to cause them to alternately engage and dis- 4 engage saidnuts whereby sai casin will "be caused to reciprocate upon'said sha and f drive said reciprocatable element. 75

5. A driving mechanism for converting rotary motion into a reciprocating motion comprising, a shafthavingright and left-hand spiral threads formed thereupon, right Zand left-hand nuts in threaded engagement with 30 said shaft, -an axiall movable casin sur- `rounding said shaft a a ted to hold sai nuts in spaced relation .an freely rotatable, a yoke carried by said casing adapted to.y connect with a reciprocatable e ement, co-'operat- 85 ing clutch members carried by said nuts and sald'casing, toggle devices' co-operating with said clutch members adapted when actuated to cause them to engage and disengage, a toggle operating means projecting beyond the 90 ends of said casing connected with said toggles, stops at the ends of said shaft adapted to engage said toggle operating means and actuate said toggles whereby said casing and yoke will be caused to reciprocate upon said 95 shaft as it is driven in one direction. 6. A driving mechanism for converting r0.- tary motion into a reciprocating motion coml prising, a shaft havingright and left-hand spiral threads formed thereupon, right and 100 left-hand nuts in threaded engagement with said shaft adapted to be driven there along when held againstl rotation, a casing surrounding said shaft adapted to hold said nuts in spaced relation and freely rotatable, a yoke 105 carried by said casing/adapted to connect l with a reciprocatable element, co-operatin coneclutch members carried by said nuts an said-casing, toggle devices co-operating with Y Asaid cone clutchumembers adapted when ac- 11 tuated to cause them to engage and disen-l gage, .to thereby grip and release said nuts 4 and thus cause said casing to 'reciprocate upon.

said shaft, .stops at the ends of said shaft 5 adapted to limit the movementofv said casing, and means carried by said casing adapt- `ed to engage said stops and actuate said toggle's, whereby said casing and yoke will be 5 caused to reciprocate as the shaft is driven in no one direction. Y e 7. In a to le mechanism for actuating anfnular clutc 'memberssurrounding a rotating shaft the combination of, a rotatable y so shaft, a stationary abutment surrounding said shaft, a plurality of axiallyd movable clutch elements, a pair of toggles on opposite side of said shaft disposed between tsaid abutlnient vand. said movable clutch elements .55 adapted to move said clutch elements into y 13 

